Fish
Common Minnow
Phoxinus phoxinus · also called European minnow
In the sunlit shallows of a gravelly stream, a shoal of minnows darts as one, the males flushed red and black in the breeding season.
Overview
The common minnow, Phoxinus phoxinus, is a Least Concern carp relative of clear, cool streams, rivers, and lakes across Europe and northern Asia. Its tiny size, shoaling, and alarm chemical make it one of the best-known small freshwater fish of the region.
A fish with a built-in alarm
If a predator injures a minnow, a chemical from its skin warns the shoal, which scatters at once, an early example of chemical communication between animals.
Status
Least Concern, widespread and common.
Common Minnow: common questions
What is the minnow's alarm substance?
When the skin is injured, it releases a chemical that warns other minnows, causing the whole shoal to flee.
Why do male minnows turn red?
In the breeding season, males develop a red belly and throat, a blackish head, and rough white tubercles.
How big is a common minnow?
It is usually only 6 to 8 cm long.
Where is the common minnow found?
It lives in clear, cool streams, rivers, and lakes across Europe and northern Asia.